| Author | Message | ||
     anonymous |
For a chemistry demonstration, I want to do the reaction of powdered aluminum and ground iodine. I can make the similar reaction work with zinc (powdered zinc + ground iodine, a couple drops of water as a catalyst. Purple cloud of sublimed iodine results), but I can't make the aluminum work. I can't figure out why the zinc would work and the aluminum would not: aluminum is more reactive. I've been doing the two experiments exactly the same (changing only the type of metal). The aluminum reaction is supposed to be stronger than the zinc one, even producing a flame. Any hints? | ||
| Simon Quellen Field (Sfield) |
Aluminum is protected by a thin coating of aluminum oxide. With zinc, the bare metal can touch the water and iodine. You may need something to overcome the protective oxide barrier -- perhaps some impurities in the water or some potassium iodide in the iodine powder. Try a slightly acidic water and see what happens. Ask the people who describe the reaction on their web sites: "http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA1/R1MAIN/CD1R1260.HTM" "http://chemmovies.unl.edu/chemistry/redoxlp/a10.html" | ||
| I. Dimov (Overrider) Junior Member Username: Overrider Post Number: 6 Registered: 12-2005 |
my chem teacher heats the stuff up, to put in extra E. |
